The Mistake-of-Fact Defense: Mistakes Made

A Texas criminal defense attorney presenting a mistake-of-fact defense to a jury

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A mistake-of-fact defense can apply when the defendant’s mistake, which was based on a reasonable belief, negates their guilt in relation to the crime.

The mistake-of-fact defense is an affirmative defense, meaning it is not an attempt to prove the defendant did not commit the alleged crime. Instead, the idea is to forward credible evidence in an effort to negate the defendant’s criminal liability in the matter. Once a defendant raises an affirmative defense, the burden of proof shifts to the defense.

The State of Texas’s stance on the mistake-of-fact defense is complicated – and many would say incomplete. As such, if you have been charged with a crime of any kind, start building your strongest defense right away with the help of an experienced Killeen criminal defense attorney.

Is the Mistake of Fact Reasonable?

In “Mistakes with the Mistake Defense in Texas Criminal Law,” two great examples are considered in relation to the mistake-of-fact defense:

  • A hunter who believes he or she is shooting a deer but, in reality, shoots another hunter

  • A bicyclist who believes he or she is grabbing his or her own bike out of the rack but takes someone else’s instead

In such instances, the would-be murderer and bike thief can look to their respective mistaken beliefs as their respective mistake-of-fact defenses – on the premise that the necessary intent to commit the crime in question was absent. In Texas, however, the accused’s mistaken belief must be deemed “reasonable,” which often becomes the sticking point.

When we consider the hunter and the bicyclist above, the mistaken belief that led to the criminal actions must have been reasonable to begin with, which means that a reasonable person in the same situation would come to the same conclusion.

Bypassing Mistake-of-Fact Jury Instructions

Many mistake-of-fact cases are tried without requests that mistake-of-fact instructions be submitted to the jury. This means that juries often do not understand that the burden of proof rests on the defense in mistake-of-fact cases.

Consider a Texas case in which a mother was convicted for knowingly harming her son in scalding hot water. The conviction was overturned on the basis that the state failed to apply the necessary element of culpability to the alleged crime, which means it did not prove that the mother intentionally harmed the child or knew that she would harm the child.

In other words, the state was on the hook for disproving the woman’s claimed belief that the water was not hot enough to harm the child.

However, if this case had been retried, the jury likely would have been instructed on the mistake-of-fact defense. In the end, though, the mother was likely better off without it. Had the jury received the mistake-of-fact instructions, any negligence (or unreasonable mistaken belief) on the part of the mother would support a conviction.

Without the mistake-of-fact instructions, the woman’s attorney could validly argue that the mother’s mistake – regardless of how reasonable or unreasonable – meant that there was a reasonable doubt regarding whether the mother intended to harm her child or whether she recognized the danger involved.

Due to this legal glitch, many criminal defense attorneys forgo submitting mistake-of-fact instructions to juries.

The Distinction between Unreasonable Mistakes and Dishonest Mistakes

Determining whether a defendant’s mistake of fact boils down to an unreasonably mistaken belief or a dishonest claim of mistakenly believing something generally hinges on what jurors believe they would have thought in similar situations.

Jurors typically see themselves as reasonably prudent people against whom reasonable beliefs and behaviors can be measured. As such, when a defendant claims a mistaken belief, a juror who cannot imagine holding the same belief is likely to doubt the defendant’s mistake-of-fact position.

Considering the case involving the mother who scalded her child, the following scenario represents a natural progression of a jury’s deliberation in relation to a mistake-of-fact defense:

  • The jurors believe they are reasonable people.

  • The jurors believe that they would have known the water was dangerously hot.

  • The jurors believe, therefore, that the defendant knew the water was dangerously hot and, as a result, believe the defendant is lying.

Where Can the Defense Turn?

A Killeen defense attorney can bring a strong mistake-of-fact case, highlighting the defendant’s intention-negating belief, without requesting that mistake-of-fact instructions be read to the jury. The problem is that both of the following are possibilities:

  • The prosecution can request the instructions – in response to them being beneficial to the defense.

  • The judge can require the instructions out of concern related to a reversible error.

At this point, the mistake-of-fact defense can become something of a catch-22.

The Amber Guyger Case

An especially complicated example of a Texas mistake-of-fact defense is the Amber Guyger case. The Texas Tribune shares that Dallas police officer Amber Guyger had just completed a 14-hour shift in 2018 when she returned home, allegedly mistook the apartment one floor above hers as her own, entered the apartment’s slightly opened door, and shot and killed the unarmed occupant.

The victim, Botham Jean, was a 26-year-old employee of the accounting firm PricewaterhouseCoopers who was eating ice cream on his couch at the time.

The Castle Doctrine

In this case, the judge allowed jurors to consider what is known as the castle doctrine, which refers to a bill passed in Texas in 2007 that says when you’re in your home, car, or business, the use of deadly force to protect yourself is presumed reasonable.

In castle doctrine cases, the jury has to interpret the amount of force used as being reasonable unless the prosecution can prove beyond a reasonable doubt that it was not. The castle doctrine can apply to the use of deadly force for self-defense when the following apply:

  • The defendant believed the person against whom deadly force was used was on their property illegally.

  • The defendant reasonably believed that the deadly force used was immediately necessary.

  • The defendant did not provoke the person against whom deadly force was used.

  • The defendant was not engaged in a criminal pursuit – other than a minor traffic offense – at the time the deadly force was used.

The Castle Doctrine in Combination with Mistake of Fact

Guyger’s case is further complicated by her claim that she was operating under a mistake of fact – Guyger believed she walked into her own apartment when, in fact, she walked into the apartment of the young victim.

This mistake of fact allows the case to tie in the castle doctrine defense, allowing defendants to protect themselves in their homes. Guyger’s belief that she was in her own apartment had to be considered reasonable for mistake of fact to apply – as discussed above.

In this case, the trial judge gave the jury instructions on the mistake-of-fact defense, which means the defense had the burden of proving Guyger’s belief was reasonable. The castle doctrine – a stand-your-ground defense – was allowed predicated solely on Guyger’s mistake-of-fact defense, which made for a complicated and controversial defense strategy.

The Prosecution’s Stance

The prosecution pointed out several cues that should have tipped Guyger off about being on the wrong floor and in the wrong apartment, including:

  • On the way to the apartment, Guyger walked down two long hallways passed 16 separate apartments.

  • She stopped at what she thought was her own apartment, but she failed to notice the bright red doormat that greeted her. She had no doormat at her own apartment exactly one floor below.

  • When she went to use her key, she realized that the door was ajar and, at this point, heard someone within.

The New York Times Fleshes Out the Case

The New York Times reports that the jury in this case was not tasked with determining if Guyger shot her neighbor, which she did, but with deciphering her perception and intent in relation to the act. While at least one senior Texas law enforcement investigator testified that the officer’s belief that she was confronting an intruder justified the shooting, not all agreed.

Guyger’s Testimony

Guyger testified in her own defense, and her testimony included all the following:

  • She was returning from a long day on the job and was speaking with her police partner – with whom she was having a relationship – at the time she pulled into her parking garage.

  • She inadvertently parked on the wrong floor. The prosecution contends that this speaks to her distraction at the time.

  • Instead of heading to her apartment, 1378, she went to apartment 1478, which is one floor above.

  • Along the way, she did not encounter anyone or notice anything that struck her as odd or out of place.

  • She was carrying her heavy gear when she went to use her key but noticed that the door was ajar and heard movements coming from within.

  • She pulled out her gun, pushed the door open with her left arm, and called for the person she thought was an intruder to show his hands.

  • The man used a “fast-paced walk” as he approached her, shouting, “Hey, hey, hey.”

  • She fired her weapon at the man twice, hitting him once in the torso.

Guyger testified that she was afraid he was going to kill her.

The Prosecution’s Evidence

For the prosecution’s part, it offered all the following in the way of evidence:

  • Prosecution witnesses testified that the man was shot either while rising to a standing position or while “in a cowering position” when attempting to hide behind a low wall in his apartment.

  • A pathologist with Dallas County testified that the victim was killed by a bullet that traveled diagonally downward through his body.

  • Several of the man’s neighbors testified that they didn’t hear Guyger’s verbal warnings to show his hands. When Guyger said on the stand that she couldn’t say why they had not heard her, the prosecutor replied, “Because you didn’t say it.”

The prosecution also did their best to cast doubt on the sincerity of Guyger’s concern after the fact – saying that she did very little to help the man. While she testified to briefly attempting CPR, the prosecution noted that she failed to implement nearby aids that could have ended his traumatic bleeding.

The prosecution also drew attention to Guyger’s stone-cold demeanor, which was captured on a police car video and┬ádepicted her calmly swiping through her phone while the victim’s body was rolled by on a stretcher. They also turned to flirty banter she texted with her partner just two days after the shooting.


Guyger was ultimately sentenced to 10 years in prison for the crime of murder. This conviction and sentence were upheld at both the state and federal level.

Charged with a Crime? Consult with an Experienced Killeen Criminal Defense Attorney Today

Brett Pritchard at The Law Office of Brett H. Pritchard in Killeen, Texas, is a focused criminal defense attorney who is poised to harness his expansive experience and legal skill in fierce pursuit of your claim’s best possible resolution. To learn more, don’t wait to contact us online or call us at (254) 781-4222 today.

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